Middlings-purifier



(No Model.)

E.T'.BUTLER. MIDDLINGS PURIFIER.

Patented Mar. 9, 1886.

Witnesses Fig'. 1

Irnventot` ,I Sub.

Attorney N, linens. mmuumnpnnr. wumngw", D, c

NITED STATES PATENT OFFICE.

ELI T. BUTLER, OF PHILADELPHIA, PENNSYLVANIA.

IVIIDDLINGS-PURIFIER.

v51EECIIEFICA'JTION forming part of Letters Patent No. 337,370, datedMarch 9. 1886.

Application filed July 13, 1885. Serial No. 171.514. (No model.)

.To all wwm it may concern:

Beit known that I, ELI T. BUTLER, of Philadelphia, Philadelphia county,Pennsylvania, have invented certain new and useful Improvements inMiddlings-Purifiers, of which the following is a specification.

This invention pertains to machinery for purifying middlings. Middlingshave usually beeny purified in machinery involving screens or sieveswhose mesh was smaller than the coarsest of the material fed to them,the sievesperformingaveritablesiftingfunctionthat is, permitting thesmall matter to pass through and retaining the large matter. So far asthe sieves were concerned, their oilice was to effect a separation on abasis of size of material presented. Their operation was modified andsupplemented by the action of currents of air passing through them, andthe clogging ofthe sieves, due to the reception of material larger thanthe mesh, was sought to be overcome by the use of brushes. In mymachinery I make use of screens, but they do not perform the usualoffice of sieves, inasmuch as they vreceive no material not capable ofpassing through them. In my machinery the sieves perform the office ofaerial suspenders-that is, they serve to suspend thematter while it isacted upon by air-blasts. The separation effected by the sieves is aseparation due to the difference in gravity ofthe particles,

rather than to a differencein the size of particles. I cause currents ofair to pass horizontally between two vibrating screens the mesh of whichis coarse enough to permit thepassage through them of the largestmaterial fed to the screen.

My invention will be readily understood from the following description,taken in connection with the accompanying drawings, in which- Figure 1is a vertical longitudinal section of my improved purifier, the sectionbeing taken upon line b of Fig. 2, and the direction of View thebolting-reel from which the middlingspurifier receives its supply ofmiddlings, this reel being supplied with a proper grade of cloth in theusual manner; B, the casing of the purifier, the same being in simplebox form, as usual in this class of machines; C, a screen-holding framedisposed horizontally within the casing; D, the hangers by which thisscreen-frame is suspended in the casing; E, the usual eccentric by whichthe shaking motion is given to the screen-frame; F, three parallelscreens carried by the screenframe, and formed of gauze two to twelvegrades coarser than the gauze of the primary screen A; G,ahorizontalair-conduitunder the roofof the casing; H, an adjustableadmission-gate, placing the conduit G in communication with thehorizontal screen at the head of the machine; J, a similarly-arrangedgate at the tail of the machine; K, asuction-fan arranged to draw airthrough the gates from above the shaking screens; L, air-inlets at thehead of the screenfr'ame, between the screens; M, an air-inlet to thecase ofthe machine at its head, below the screens; N, a chamber forreceiving the clean middlings; O, aout-off chamber for receivingmiddlings less cleaned than that received by the chamber M; P. thetailings-chamber; Q, a pivoted adjustable partition between the chambersN and O. by means of which the cut-off chamber may be caused to receivethe earlier or later discharges from the screens; R, the feed-hopper ofthe puritier, and S angular crossfpartitions at the head of the machine,over the screens arranged to deliver the middlings as received at thehead of the upper screen.

-fThe middlings fall upon the head of the upper screen, and, owing tothe'large mesh of the gauze,would naturally fall directly through thegauze, there being no overloading of the screen. The direct passage ofthe middlings through the upper gauze is retarded by the upward currentsof air through the gauze. As a consequence of this retardation, most ofthe middlings will advance along thevupper screen toward the tail.During this advance the middlings on the upper screen Will be subjectedto the upward currents of air passing through the screen, and the fluffymatter will be carried up and out of the machine by the fan. As themiddlings become cleaner, they become less susceptible to the retardingaction of the upward 'air-currents, and they con= sequently fallthroughthe upper screen onto IOO the middle one. On this screen the middlingsare again subjected to the action of the upward air-currents, and themiddlings passing through this screen onto the lowerone become againsubjected to the action of these currents. The cleanest of the middlingswill find its way quickly downward through all of the screens into thechamber N before these middlngs have had an opportunity to advance far-toward the tail of the machine. Those middlings which are less cleanwill be capable of a further advance toward the tail before they can getthrough the screen, and these middlings will find their way to thechamber O. The tailings will have passed the entire length of thescreens before they can have passed through the three screens, and theyconsequently fall off into the chamber P. The partition Q is to be soset in relation to the head ofthe screen that the two chambers N and Owill receive their proper grades of middlings, and all of the lowerchambers may be supplied with outlet spouts or conveyers, as is usual.

The advance of the middlings along the screens would naturally begoverned by the rate of retardation to their passing downward throughthe screens, this rate of retardation being fixed by the strength of theaircurrents. The gates H and J provide for regulating the direction ofthe air-currents as well as the strength of these currents. If the gateH be Widely opened, and the gate. J correspondingly closed, thedirection of the air-currents will be almost directly through thehead ofthescreen, while if the degree of opening of the two gates be reversedthe directions of the air-currents will be toward the tail of themachine as well as upward. By proper adjustment of these gates theintensity of the longitudinal currents may be regulated, so as to causethese currents to move the material toward the tail of the screen at anyrate desired, whereby the time of their subject-ion to the purifyingaction is brought under perfect control.

It will be readily understood that there may be as many of the screens Fas are desired, so long as there are two of them; butin practice threescreens, as shown, will be found'preferable to a greater or less number.

vI deem it proper to state that my improved purifier involves theemployment of a number of old and Well-known devices, to which 'I lay noclaim, my improvement being intended to overcome recognized defects inthe old devices as heretofore arranged and employed. Thus to arrangeseveral sieves of silk cloth, wirecloth, or screen-iron in a singleshaking frame, and to allow the material to fall from one to the other,is not at all new; but in these multiple sieves the grade of the lowersieves has been made successively finer, the sole object being thatmattertoo coarse Vto pass through the upper sieve would pass over thetail of that sieve, while matter passing through that sieve would againbe graded and separatedby the following finer sieves, and so on, eachsieve in its' turn delivering over its tail a grade of material coarserthan its sieve, but ner than the sieve above, at the same timedelivering through its mesh a material finer than its mesh, to befurther graded by the lower sieves. In my device the individual sievesare all coarser than the material which falls upon them, and theytherefore do not exercise a grading eiect upon the material by reason ofthe relation of the size of mesh to size of material. The oldmultiplescreens referred to have sometimes been arranged with individualscreens, one over the other, and, again, with individual screenssucceeding each other endwise, the screens all being in asingle shakingframe; but in all cases each screen vhas been arranged to receive itsmaterial from a precedingscreen of eoarser mesh, the entire system beingbased upon gradation of material by the gradation of mesh of sieve. Inmy machine I obtain diii'erent grades of material from one grade ofsieve-mesh.

' To cause an upward current of air to pass through the sieves, so as tohold the material,

as vit were, in suspension over the sieves, and

to blowthe iluHy matter from the `suspended material, is old and verycommonly employed in middlings -puriiiers and other analogousseparatingmachines, I employ this well- (known air-blast system inconnection with a multiple sieve whose mesh is coarser than any of the,material received by it, the air-b1ast serving, as of old, to suspendthe material, but also to advance the material toward the tail of thesieves, whereby the material is floated in an open manner for a greateror less time over a sieve whose mesh is coarser than the material, theability of the heavier materials to pass through the coarse sieves inspite of the lifting effect of the blast being utilized in eii'ectingthe work of purification and the gradation of neness of matter not drawnofi' by the air-current.

To deliver material upon the sieve whose mesh is coarser than thematerial is not new, the plan beingvfully set forth in United StatesVLetters Patent No. 311,808, granted to myself and another party onFebruary 3, 1885. The `material was received upon a single vibratingsieve whose mesh was coarser thanthe material, and an upward current ofair kept the material more or lessjn suspension; but it was found thatthe material would pass through the sieve improperly purified, even whenthe sieve 'had such a fine mesh as to greatly interfere with therapidity of the purifying process. We sought to overcome this difficultyby pasting strips of cloth to the sieve, thus producing a sieve partsolid and part sieve-like, the in tention being that the materialpassing tail ward over the sieve should not at all timeshave anopportunity of dropping from thesieve, its opportunity for droppingbeing restricted to the open Aportions between the strips. Even withthis modification the machine has not been at all satisfactory, besidesbei-ngfcumbersome and expensive, and of very limited IOO capacity whencompared With my improved machine.

I claim as my invention- In a purifier, the combination, with a pri- 5mary screen adapted to deliver material to the purier, of a shakerconstructed with parallel screens, one above another, and of a meshcoarser than that of said primary screen, and with air-inlets betweenthe heads of ther 1o screen, a hopper delivering from the primary Screentothe head of the upper shaking screen,

an inclosing casing having air-inlets below the screens and adjustableair-exits above the opposite ends of the upper shaking screen, and meansfor producing suction at said adjustable 15 air-exits, substantially asand for the purpose set forth.

ELI T. BUTLER.

NVitnesses:

THoMAs EvANs, ALEXANDER RICKEY.

